1. Field of the Invention
This invention relates generally to a lighted fixation device and, more particularly, to an LED fixation device for use in topical anesthesia eye surgery, such as clear cornea cataract surgery.
2. Discussion of the Related Art
Cataract or opacification of the lens in the human eye is a prevalent medical condition and a major cause of preventable blindness worldwide. The exact etiology of this condition is unknown, but cataracts are usually thought to be changes that occur in the lens as a result of aging. Cataracts are also seen in certain ocular or systemic diseases, in ocular trauma and after exposure to some systemic drugs.
Currently cataracts can only be treated surgically. The current treatment involves surgically removing the human lens and implantating an intraocular lens. Small incision techniques, state of the art biomedical instrumentation and safe and stable intraocular lenses have combined to make cataract surgery one of the safest and fastest procedures in medicine. Cataract extraction and lens implantation can be achieved with minimum pain and discomfort. With the advent of small, suturless clear corneal incisions, and by using foldable intraocular lenses, cataract surgery is performed with less trauma, faster and with greater control, and has allowed some surgeons to use topical anesthesia as the procedure of choice. Pediatric cases are mostly performed under general anesthesia, however.
With the improvement of surgery techniques and equipment, most major complications related to cataract surgery are on the decline. However, complications associated with regional block anesthesia still present a significant problem. For regional block anesthesia procedures, it is common to significantly sedate the patient in combination with the block. This level of sedation can cause respiratory compromise. Systemic complications include allergic reactions, systemic toxicity, intrarterial injection and optic nerve sheath injection. For an experienced surgeon, these complications are rare, but they can and do happen.
Topical anesthesia obviates most medical contraindications to cataract surgery. Topical anesthesia avoids potential complications of retrobulbar or peribulbar block which can include globe perforations, retrobulbar hemorrhage, optic nerve atrophy, retinal vascular occlusion and ptosis. Topical anesthesia gives an extra margin of safety for the medically compromised patients. Topical anesthesia also allows for a fast visual rehabilitation time. Most patients may go home from the procedure without a patch and see clearly just 30 minutes after phaco with a clear comeal incision under topical anesthesia.
Topical anesthesia does not require special training or a learning curve, and can be given to the patient in the preoperative area by staff along with dilating drops. It can be repeated at any time during the preoperative period prior to making the incision. Patient anxiety can usually be easily controlled with communication. Assuring the patient that there will be no pain and reporting the progress of the procedure will usually calm the patient's anxiety. Mild sedation can be used as an adjunct if needed.
The use of topical anesthesia during eye surgery does have certain disadvantages, however. Perhaps the most important disadvantage for a surgeon is eye movement during various stages of cataract surgery. Eye movement, and most importantly eye positioning, is crucial for most stages of the surgery. Undesired eye movement or position might require extra steps that may cause introperative or postoperative complications. Patients who are unable to cooperate or follow commands, including patients with dementia, nystagmus, deafness or inability to communicate because of language, do better under a regional block with IV sedation.
Even for cooperative and preoperatively well-selected patients, it sometimes becomes difficult to maintain a desirable eye position at the start or during the surgical procedure. The bright microscope light is sometimes hard to look at directly and some patients try to avoid it. Positioning the microscope to avoid direct illumination might compromise obtaining a good red reflect that might be necessary for some critical steps. Furthermore, since the fellow eye is usually covered, patients sometimes lose orientation to space and are not able to follow surgeon's directional commands to realign the eye, such as looking down, left or any other direction. Patients can move their eye between stages of surgery, and this requires another command by the surgeon to realign the eye or to reposition the microscope or manually maintain the eye position using an instrument. The latter requires the surgeon to perform extra manipulation of the eye.
What is needed is a procedure or device that helps a patient maintain his or her eye directed in a preferable direction during eye surgery, and that does not employ anesthesia or sedation. It is therefore an object of the present invention to provide such a device.